1. Field of the Invention
The present invention relates to an image stabilizing apparatus that performs a shift movement of a lens in order to correct an image blur.
2. Description of the Related Art
Previously, in an optical apparatus such as a digital camera or a digital video camera, a shift unit (an image stabilizing apparatus) that performs a shift movement of a lens in order to correct an image blur generated by a hand shake has been known. In Japanese Patent Laid-Open No. 2002-196382 discloses an image stabilizing apparatus that moves a correction lens unit. This image stabilizing apparatus is a shift unit of so-called moving coil type, which has a driving magnet disposed on a base member at a fixed side and has a yoke and a coil disposed on a shift member at a movable side.
Since a magnetic suction force acts between the driving magnet and the yoke, there is a position where the driving magnet and the yoke magnetically come into balance with each other. Accordingly, when a position relation between the driving magnet and the yoke is changed from the balanced position, a force that is to go back to an original position (a pulling force) acts. As a result, the shift unit that includes two drivers that drive the shift member in a vertical direction (a pitch direction) and a horizontal direction (a yaw direction) in a plane orthogonal to an optical axis generates the pulling force of one driver in accordance with the position change of the other driver.
Japanese Patent Laid-Open No. 2002-196382 discloses an image stabilizing apparatus that reduces a pulling force in a pitch direction driver. In this image stabilizing apparatus, a protrusion that protrudes in an optical axis direction is provided on a yoke. The strength of a force caused by magnetism is inversely proportional to the square of a distance. Therefore, when the shift member moves in the plane orthogonal to the optical axis and the distance between the driving magnet and the protrusion is changed, the pulling force that acts between the driving magnet and the protrusion acts in a direction in which the movement is facilitated.
However, since the pulling force is generated in the yaw direction driver in this case, a moment that rotates the shift member in the plane orthogonal to the optical axis is generated. Therefore, the shift member is freely rotated during the image stabilizing operation. When the shift member contacts a fixed member by the rotational motion, a collision noise is generated and an image may also be fussy. In addition, when a part is damaged by the contact, the drive of the shift member may be disturbed after that.
Japanese Patent No. 3229899 discloses an image stabilizing apparatus that is provided with a guide shaft that limits the rotation of a shift member in a plane orthogonal to the optical axis direction.
However, when the guide shaft as disclosed in Japanese Patent No. 3229899 is newly provided, the reduction in size of the image stabilizing apparatus is prevented. In addition, since the configuration of the apparatus is complicated and the number of parts is increased, it is difficult to reduce cost.